1. Field of the Invention
The present invention relates to a bedding, such as futon mat (Japanese mattress), mattress, pillow, cushion and so forth.
2. Description of the Related Art
When a user does not change attitude on a bed or chair frequently enough, or a particular portion of the body may be depressed for a long period of time to cause ectrimma (so-called bed sore).
As one kind of bedding for preventing ectrimma, there has been known a doughnut form cushion having a central through hole formed by enclosing a cushion body in an annular shaped cover.
Such cushion has been known as capable of preventing the occurrence or deterioration of ectrimma by absorbing body pressure to be exerted on a particular portion of the body, particularly on the affected part by the cushion body. (see Japanese Utility Model Registration No. 3031011, particularly FIGS. 1 and 3).
However, even though the cushion may protect the affected area by a necessary cushioning effect of the cushion body, it is possible that the user may feel pain even by contacting the cushion body. In case of the doughnut shape cushion, unless it is used in a condition where the central through hole is aligned with the affected part, the cushion body inherently contacts the affected area to cause inconvenience.
On the other hand, in case of the futon mat or mattress which does not have the central through hole of the cushion, the cushion body inherently contacts the entire affected part to cause similar shortcoming.
Furthermore, even in the case of a pillow enclosing the necessary cushion body, and if tumefaction or the like is present in a head portion, it is inherent that the affected part is depressed.